Synchronized contact watch

ABSTRACT

A battery-powered electric wrist watch in which a known fixedfrequency time base unit, such as that having a quartz oscillator and a frequency divider, is made operative to give better timekeeping by association in a simplified way with the motive unit of the watch through the use of a combination of selected particular functional units, viz., (1) the means for directly actuating the wheels of the watch is an oscillatory balance wheel assembly whose frequency of oscillation is made dependent on its oscillation amplitude over a working range of frequency values; (2) the impulsion of the balance wheel is by impulses from an electromagnetic motive unit of coil and permanent magnet whenever battery current flows in the drive coil; and (3), the flow of current in the drive coil, which is made to occur in intermittent pulses by a contactor associated in known fashion with the balance wheel, is controlled as to its duration (pulse width) and particular timing by the AND-function effect of the connection of the contactor and the battery in series with two terminals of a transistor whose control terminal receives a train of output pulses of fixed frequency directly from the frequency divider of the fixed-frequency time base unit, to make the transistor intermittently conductive for periods of fixed duration.

United States Patent Zatsky [54] SYNCHRONIZED CONTACT WATCH [72] Inventor: Norman Charles Zatsky, Briarcliff Manor, N.Y.

[73] Assignee: Timex Corporation, Waterbury,

Conn.

[22] Filed: April 5, 1971 [21] Appl. No.: 131,237

[52] US. Cl ..58/23 AC, 58/28 B, 318/128 [51] Int. Cl. ..G04c 3/00 [58 Field of Search..58/23 AC, 23 V, 28 B; 3l0/8. 3; 318/128,132,134

[56] References Cited UNITED STATES PATENTS 3,451,210 6/1969 Helterline, Jr. et al. ..58/26 2,424,833 7/1947 Korman ..58/23 AC 3,167,906 2/ 1965 Fukata et a1. ..58/23 V 3,212,252 10/1965 Nakai ..58/23 R 3,282,042 11/1966 Schaller ..58/23 V 3,292,064 12/1966 Watters ..58/23 R 3,309,590 3/1967 Reich ..318/132 X 3,407,344 10/1968 Bansho ..318/132 X Primary Examiner-George H. Miller, Jr. Attorney-Richard A. Joel 1 Oct. 24, 1972 [57] ABSTRACT A battery-powered electric wrist watch in which a known fixed-frequency time base unit, such as that having a quartz oscillator and a frequency divider, is made operative to give better timekeeping by association in a simplified way with the motive unit of the watch through the use of a combination of selected particular functional units, viz., (l) the means for directly actuating the wheels of the watch is an oscillatory balance wheel assembly whose frequency of oscillation is made dependent on its oscillation amplitude over a working range of frequency values; (2) the impulsion of the balance wheel is by impulses from an electromagnetic motive unit of coil and permanent magnet whenever battery current flows in the drive coil; and (3), the flow of current in the drive coil, which is made to occur in intermittent pulses by a contactor associated in known fashion with the balance wheel, is controlled as to its duration (pulse width) and particular timing by the AND-function effect of the connection of the contactor and the battery in series with two terminals of a transistor whose control terminal receives a train of output pulses of fixed frequency directly from the frequency divider of the fixed-frequency time base unit, to make the transistor intermittently conductive for periods of fixed duration.

10 Claims, 7 Drawing Figures FIEWEW PATENTED 0m 24 m2 SHEET 2 OF 2 72 meal/ma DI V/DER QUAR TZ lfl OSCILLATOR FIG. 3

corvmcr CL 0550 v INTERVAL TIME , FIGAA FIG-4B OUTPUT 0F DIV/DER C/PCU/f CURRENT PULSE 70 new: co/z.

FIG. 4C

AMPZ III/0E INVENTOR. A ORMA/V C. 24 rsKY DEA/EV FIGS 1 SYNCHRONIZED CONTACT WATCH BACKGROUND OF THE INVENTION The use of quartz or like oscillator of highly stable frequency in conjunction with a frequency divider to control the frequency of a slave device has long been known, as evidenced by Jones U.S. Pat. No. 3,110,853 and patents of even earlier date; but heretofore the application of this desirable means of control to an electric watch has posed problems.

Relatively recent examples of proposals that have been made are to be found in the patents of Nakai U.S. Pat. No. 3,212,252, Watters U.S. Pat. No. 3,292,064, Schaller U.S. Pat. No. 3,282,042 and Helterline U.S. Pat. No. 3,451,210. In these, the wheels of the watch are driven by either a conventional oscillatory balance wheel or a tuning fork unit, in which oscillation frequency is relatively independent of oscillation amplitude, and which is impulsed intermittently at a controlled point in the oscillation cycle when battery current is applied to the drive of the electromagnetic motive unit; but the control of the current pulses to the drive coil involves the use of an additional pick-up or sensing coil to control a transistor as the current controlling switch, and the tie-in to the time base unit involves either a combination of signals in the transistor output or special circuitry by which pulses from the pick-up coil are combined in one way or another with the frequency-divided output of the quartz oscillator to develop a combined signal for application to the base of the transistor.

The present invention provides a simplified and effective system for using such a time base unit in a battery-powered wrist watch by the combination of such a unit in a new way with selected particular functional units for the DC. battery-powered motive unit of the watch, comprising the following:

1. For the direct transmission of driving forces in the known way to the wheels of the watch, a balance wheel unit of the kind in which the frequency of oscillation is made to be dependent on oscillation amplitude, as for example by an arrangement of the usual regulating pins in such close physical relation to the helical hairspring that they bear upon it variably to change the natural frequency of oscillation as the amplitude of oscillation varies, such a balance wheel unit being known per se from Conrad U.S. Pat. No. 2,183,062;

2. An electromagnetic motive unit for the balance wheel which consists of a drive coil and a permanent magnet, the coil preferably but not necessarily serving as the mobile element and therefore, being the element mounted on the balance wheel; such a motive unit being either of the unidirectional impulse type using two poles of opposite polarity to generate simultaneous impulses on the two sides of the coil, once in each full oscillation, as in U.S. Pat. No. 2,976,435 (and cf. Conrad, above), or of the bidirectional type as in French Patent No. 1,277,507, using three poles and a doubleaction contact, but with the same two-poles action in a given direction once in each half-oscillation according to the principle of Fery set forth in French patent No. 677,304 of 1908 and its additions Nos. 36,036 and 36,434;

3. A contactor which is in a series loop with the battery and the drive coil and which is closed briefly, to give a conductive state, at a particular point or points in each half or full oscillation, by the engagement of a conductive pin on the balance wheel or its staff with the free end of a resilient fixed contact, as in the patents identified in paragraphs 1 and 2 above; and

4. A triode transistor having a control electrode and two other electrodes which are connected in the series loop including the battery, the drive coil and the contactor, thus creating with the contactor and AND unit in the sense that current flows in the loop only when both the contactor and the transistor are conductive, the transistor having its control electrode, e.g., its base, directly connected to the frequency divider output to receive a train of pulses of stable frequency which make the transistor intermittently conductive for time periods of fixed duration.

With this system, stabilization of the timekeeping is effected by the action of the AND network in fixing the duration (width) of the pulses of current applied to the drive coil of the motive unit. The duration of those pulses of constant DC voltage determines the amplitude of oscillation, which in turn controls oscillation frequency because of the special amplitude-frequency characteristic given to the balance wheel assembly. As oscillation frequency varies (watch running too fast or too slow), the duration of the current pulses in the coil varies because of the resulting change in phase as between the varying-duration conductive periods of the contactor and the fixed-duration conductive periods of the transistor, with consequent change in the duration of their coincident conductive periods.

Synchronizing systems have been known before in which the duration of impulsion of a driven unit was varied by variation of the coincident conduction periods of two devices which were placed in the power supply line to a drive coil and which had intermittent conductive periods, the conductive periods of one such device being determined by the driven motive unit and those of the other such device being determined by a reference signal. See Conrad U.S. Pat. No. 2,183,062, cited above, in which a contactor worked intermittently by a balance wheel was in series with a rectifier that passed the half-waves of a received alternating current supply of power for driving the'motive unit.

Also, Lavet U.S. Pat. No. 3,207,965, FIGS. 10-14, describes a master and slave system in which the master oscillator is of the tuning fork type driven by intennittent application of direct current to a drive coil 14 through a transistor TR-l controlled by pulses generated in a sensing coil 13 associated with the fork; and the synchronized receiver or slave unit, either an oscillatory or rotary motive unit, is driven by coils 34-36 which are in parallel with the master drive coil 14 and which receive current during the coincident conductive periods of the transistor TR-l at the master oscillator and a device (either another transistor TR-2 or a circuit breaker) worked by the receivers motive unit (as through pick-up coil 37), there being in some cases a frequency dividerbetween the master unit and the receiver unit. See also the French patents of Hatot No. 1,092,411 (FIG. 12); the sixth Addition No. 73,591 thereto; and FIG. 38 of the third Addition No. 80,213 to No. 1,090,564.

The present invention is illustrated by the system described below with reference to FIGS. 1 to 5 of the drawings, in which:

FIG. 1 is a schematic diagram of the balance wheel (BW) and its hairspring and regulating pins as adapted to make the natural frequency of oscillation of the balance dependent on its amplitude of oscillation over a working range of oscillation frequency changes;

FIG. 2 is a side view of a portion of the invention shown in FIG. 1; 1

FIG. 3 is a schematic diagram of the electrical system including the motive unit for the balance wheel, the AND network and the time base unit;

FIG. 4 is a chart in three parts, 4A to 4C, of therelative closure or conductive intervals of the contactor and the transistor, and of the current supplied to the drive coil during the intervals when the two are simultaneously closed, i.e., are both conductive;

FIG.- 5 is a qualitative chart of oscillation frequency versus amplitude for the balance wheel assembly of FIGS. 1 and 2.

DETAILED DESCRIPTION OF THE INVENTION Referring now to the drawings, the synchronized contact watch of the present invention includes a high frequency oscillator which serves as a time base or source for timing signals receiving energy from a local source 15, preferably the battery which supplies drive current to the motor of the time piece. The oscillator 10 may be a quartz crystal oscillator having a frequency in the range of 49,000 Hz or any other suitable high frequency. The crystal oscillator 10 provides a very stable high frequency signal to the frequency divider 1 1.

The frequency divider 11 comprises a plurality of dividing circuits, preferably of the complementary metal-oxide semiconductor type, which divide down the high frequency pulse rate from the oscillator 10 to some lower multiple of the balance wheel frequency. An output frequency of about 6 Hz would be satisfactory for a synchronizing signal being fed to the AND circuit 12. In a three-beat watch, for example, the divider output frequency would then be twice the balance wheel frequency.

The AND circuit 12 comprises a transistor 13 having its base 14 connected to the divider 11. The collector 16 is connected in series with the switch or contactor 17 while the emitter 18 is coupled to ground. To lessen the current drain of the circuit, a field effect transistor may be used in this instance. Transistor 13 and switch 17 comprise an AND arrangement for feeding drive pulses to the coil 19.

The pertinent portions of the watch of the present invention are shown in FIGS. 1 and 2. The watch comprises a front frame 31 having a dial ring 32 mounted thereon and a balance bridge 33 which is spaced apart from the frame 31. A balance wheel staff 34 is journalled in a bearing 36 in the front frame 31 and a bearing 37 in the balance bridge 33. The balance wheel staff 34 carries the balance wheel 21 which includes the electric coil 19 of round, trapezoidal, or other shape, consisting of many turns of fine wire. A magnet 25 is mounted to the dial ring 32 on one side of the coil while a magnetic shunt 38 is positioned below the coil 19.

The hairspring 39 is coupled to the balance staff 34 for regulating the movement of the balance wheel 21 which includes a contact pin 41 mounted thereon. The pin 41 is connected to one end of the coil 19 by lead 42 while the other lead 43 from the coil 19 is connected to the balance wheel 21 at 44.

A contact spring assembly 46 is mounted adjacent the balance wheel 21 and includes a body portion 47 of an insulating material, a spring contact arm 48 for engaging the energy cell 15 and a contact spring 49. The contact spring 49 is joined to the body 47 by mounting means 51 while the contact arm is joined thereto by means 52. The spring 49 extends at a right angle to its base 53 while an intermediate portion is held by damping arm 54. The free end portion of the spring 49 contacts pin 41 during the rotation of the balance wheel 21 to complete the AND circuit 12.

In operation, a synchronizing pulse is fed to drive coil 19 creating a magnetic field which interacts with the field of the magnet 25. This interaction of magnetic fields imparts an impulse to the balance 21 when the magnet 25 is in place. The magnet 25 is usually a single piece of ceramic forming in effect, three magnets and creating three magnetic fields through which the coil 19 oscillates. The three magnetic fields are arranged with alternating polarities, for example, South-North- South, at the magnet face to provide bidirectional impulsion to the balance 21. The contact spring 49 and contact pin 41 are positioned with respect to the magnets to provide self-starting.

The balance 21 acts against the restoring force of a nonlinear spring 39 which can be selected or adjusted by regulator means so that the amplitude of the balance wheel 21 increases with frequency affecting the contact closure period of switch 17, see FIG. 5. Alternately, the spring 39 can be selected to provide a balance wheel isochronism characteristic wherein the amplitude decreased with frequency. As a more practical matter, a conventional linearv spring may be employed with a special regulator (not shown) to provide the desired non-linear isochronism characteristc.

As shown in FIGS. 2 and 3, the switch 17 comprises contact spring 49 mounted to assembly 46 and extend- .ing outwardly therefrom. The spring 49 intermittently engages contact pin 41 mounted on the oscillatory balance 21 to complete the circuit path through transistor 13 to coil 19. The output of the divider 14 is fed to the drive coil 19 in the form of a variable width pulse only during the time interval that the switch 17 is closed and the transistor 13 is activated to feed pulses thereto.

Referring to FIGS. 3 and 4A, 4B and 4C, the transistor 13 operates under the control of the divider output to provide a series of synchronizing pulses P of fixed and highly stable frequency and duration shown as P in FIG. 4B. The divider 11 reduces the frequency of the high frequency or quartz oscillator 10 to 6 Hz range from an input frequency in the 49 KHz range. Current flows in the drive coil 19 only when the transistor 13 is turned on and switch 17 is closed. Switch 17 and transistor 13 thus comprise an AND circuit to control the drive pulses to the coil 19 by regulating the pulse width.

The contact closed interval P illustrated in FIG. 4A and the current pulse P in FIG. 4C vary with the motion of the balance wheel 21. Thus, if the balance wheel 21 speeds up the pulse interval P will tend to become narrower whereas if the balance wheel 21 slows down, the pulse interval P will tend to become wider. The

current pulse P to the drive coil 19 is that portion of the pulse P passed during the pulse interval P Therefore, if the wheel 2]. speeds up, the current pulse P becomes narrower because the contact closure terminates earlier in relation to P The current pulse P is, consequently varied in width to provide more or less driving motion to the balance wheel 21 in accordance with the pulse passed during the closure of switch 17.

The balance wheel 21 is coupled in a nonlinear arrangement under control, for example, of a selected hairspring 39 or a hairsprin g having a nonlinear characteristic imparted thereto by a special regulator wherein the frequency of the balance varies with amplitude. The changes in pulse width fed to the coil 19 cause changes in the mechanical amplitude of the balance wheel 21 which due to the nonlinearity of the mechanical system cause the balance wheel 21 to return to the synchronized frequency. The curve of one such system, Frequency versus Amplitude, is plotted in FIG. 5.

To summarize, the improved wrist watch comprises a quartz oscillator and divider unit 11 which are cou pled in a new and simplified manner with selected functional units. An oscillatory balance wheel 21 having a frequency of oscillation dependent upon amplitude of oscillation is one such unit while another is an electromagnetic motive unit which drives the balance wheel 21. The drive pulses to impel the balance wheel 21 are controlled both as to duration and timing by the AND-function effect of a contactor 49 in series with a transistor 13. The output divider 11 makes the transistor portion of the AND arrangement intermittently conductive for periods of fixed duration. The resultant current pulse varies with the speed of the balance wheel because the contact closure terminates earlier or later in relation to the pulses from transistor 13. The balance wheel 21 which drives the wheels of the watch is thereby synchronized by pulses from quartz oscillator 10.

The present invention, as described above, thus provides an extremely accurate synchronized watch which functions under the control of synchronizing pulses from a quartz oscillator. It is to be understood that the above described arrangements are merely illustrative of the application of the principles of the present invention. Numerous other arrangements may be readily devised by those skilled in the art which will embody the principles of the invention and fall within the spirit and scope thereof.

lclaim:

1. In a battery-powered electric wrist watch of the type in which the immediate power source for the wheels is an oscillatory balance wheel unit including a hairspring, the combination of:

means associated with the hairspring by which the oscillation frequency of the balance wheel unit is dependent on oscillation amplitude over a working range of oscillation frequency,

an electromagnetic motive unit comprising a rela tively movable drive coil and multipolar permanent magnet for imparting an impulse to the balance wheel when current flows in the drive coil, one of said elements of the motive unit being mounted for motion with the balance wheel,

a battery for supplying direct current to said drive coil,

a make-break contactor connected in series loop including said drive coil and battery and comprising a conductive element moving with the balance wheel and a flexible conductive member at one end and adapted to be engaged briefly by said moving conductive element to establish a conductive state of brief duration at a pre-determined point in the motion of the balance wheel,

a triode transistor having a control electrode and having its two other electrodes connected in said series loop to pass current of said loop when the transistor is in conductive state, and

a time base unit comprising a piezoelectric crystal oscillator unit and frequency divider network having its output directly connected to the control electrode of said transistor to apply thereto a train of discrete pulses of fixed width and frequency to render said transistor intermittently conductive, whereby the duration of current flow in said coil upon each closure of said contactor is determined by the coincidence of its conductive state with that of said transistor, thereby to control the amplitude and through it the frequency of said balance wheel oscillations.

2. A battery-powered wrist watch in accordance with claim 1 wherein:

the means associated with the hairspring comprises a regulator which causes the amplitude of the balance wheel to increase with frequency of oscillation.

3. A battery-powered wristwatch in accordance with claim 1 wherein:

the electromagnetic motive unit comprises a drive coil mounted on the oscillatory balance wheel and a multipolar magnet of ceramic material mounted on a stationary member opposite the coil.

4. A battery-powered wrist watch in accordance with claim 1 wherein:

the battery is further coupled to and supplies power to the crystal oscillator unit.

5. A battery-powered wrist watch in accordance with claim 1 wherein:

the make-break contactor comprises a pin mounted on the balance wheel and a spring contact mounted in an insulating block at one end and engaging the pin with its other free end.

6. A battery-powered wrist watch in accordance with claim 1 wherein:

the transistor comprises a field effect transistor.

7. A battery-powered wrist watch in accordance with claim 1 wherein:

the piezoelectric crystal oscillator has a frequency in the range of 49,000 Hertz and the divider output has a frequency of 6 Hertz.

8. A watch comprising:

a power source,

a high frequency quartz crystal oscillator activated by the power source,

a divider to reduce the frequency of the high frequency oscillator,

a transistor switch connected to the divider output to be intermittently operated thereby,

a contact spring connected in series with the transistor to provide an AND function effect in conjunction with the switch,

a balance wheel assembly including a balance having a low frequency of oscillation which is dependent on amplitude of oscillation, stationary magnet means, a drive coil mounted on the balance wheel for interaction with magnet means, and contact means engaged by the spring during the oscillation of the balance wheel to supply drive controlled pulses to the coil thereby synchronizing the balance wheel with a sub-harmonic frequency of the quartz crystal oscillator, and,

time display means operated by the balance wheel assembly.

9. A watch in accordance with claim 8 further including:

a hairspring coupled to the balance wheel and regulater means associated therewith to impart a nonlinear isochronism characteristic to the balance wheel wherein the frequency of the balance wheel varies with amplitude.

10. A watch in accordance with claim 8 wherein:

the contact means comprise a contact pin mounted on the balance wheel and connected to one end of the drive coil, and,

the contact spring comprises an elongated spring member fixedly mounted at one end and having a damped intermediate portion, the end portion thereof engaging the contact pin in a predetermined manner during the oscillation of the balance wheel. 

1. In a battery-powered electric wrist watch of the type in which the immediate power source for the wheels is an oscillatory balance wheel unit including a hairspring, the combination of: means associated with the hairspring by which the oscillation frequency of the balance wheel unit is dependent on oscillation amplitude over a working range of oscillation frequency, an electromagnetic motive unit comprising a relatively movable drive coil and multipolar permanent magnet for imparting an impulse to the balance wheel when current flows in the drive coil, one of said elements of the motive unit being mounted for motion with the balance wheel, a battery for supplying direct current to said drive coil, a make-break contactor connected in series loop including said drive coil and battery and comprising a conductive element moving with the balance wheel and a flexible conductive member at one end and adapted to be engaged briefly by said moving conductive element to establish a conductive state of brief duration at a pre-determined point in the motion of the balance wheel, a triode transistor having a control electrode and having its two other electrodes connected in said series loop to pass current of said loop when the transistor is in conductive state, and a time base unit comprising a piezoelectric crystal oscillator unit and frequency divider network having its output directly connected to the control electrode of said transistor to apply thereto a train of discrete pulses of fixed width and frequency to render said transistor intermittently conductive, whereby the duration of current flow in said coil upon each closure of said contactor is determined by thE coincidence of its conductive state with that of said transistor, thereby to control the amplitude and through it the frequency of said balance wheel oscillations.
 2. A battery-powered wrist watch in accordance with claim 1 wherein: the means associated with the hairspring comprises a regulator which causes the amplitude of the balance wheel to increase with frequency of oscillation.
 3. A battery-powered wrist watch in accordance with claim 1 wherein: the electromagnetic motive unit comprises a drive coil mounted on the oscillatory balance wheel and a multipolar magnet of ceramic material mounted on a stationary member opposite the coil.
 4. A battery-powered wrist watch in accordance with claim 1 wherein: the battery is further coupled to and supplies power to the crystal oscillator unit.
 5. A battery-powered wrist watch in accordance with claim 1 wherein: the make-break contactor comprises a pin mounted on the balance wheel and a spring contact mounted in an insulating block at one end and engaging the pin with its other free end.
 6. A battery-powered wrist watch in accordance with claim 1 wherein: the transistor comprises a field effect transistor.
 7. A battery-powered wrist watch in accordance with claim 1 wherein: the piezoelectric crystal oscillator has a frequency in the range of 49,000 Hertz and the divider output has a frequency of 6 Hertz.
 8. A watch comprising: a power source, a high frequency quartz crystal oscillator activated by the power source, a divider to reduce the frequency of the high frequency oscillator, a transistor switch connected to the divider output to be intermittently operated thereby, a contact spring connected in series with the transistor to provide an AND - function effect in conjunction with the switch, a balance wheel assembly including a balance having a low frequency of oscillation which is dependent on amplitude of oscillation, stationary magnet means, a drive coil mounted on the balance wheel for interaction with magnet means, and contact means engaged by the spring during the oscillation of the balance wheel to supply drive controlled pulses to the coil thereby synchronizing the balance wheel with a sub-harmonic frequency of the quartz crystal oscillator, and, time display means operated by the balance wheel assembly.
 9. A watch in accordance with claim 8 further including: a hairspring coupled to the balance wheel and regulator means associated therewith to impart a nonlinear isochronism characteristic to the balance wheel wherein the frequency of the balance wheel varies with amplitude.
 10. A watch in accordance with claim 8 wherein: the contact means comprise a contact pin mounted on the balance wheel and connected to one end of the drive coil, and, the contact spring comprises an elongated spring member fixedly mounted at one end and having a damped intermediate portion, the end portion thereof engaging the contact pin in a predetermined manner during the oscillation of the balance wheel. 